code: def test_P3():
      """Second order centrality: line graph, as defined in paper"""
      G = nx.path_graph(3)
      b_answer = {0: 3.741, 1: 1.414, 2: 3.741}
  
      b = nx.second_order_centrality(G)
  
      for n in sorted(G):
          assert b[n] == pytest.approx(b_answer[n], abs=1e-2)
  
file_path: networkx/networkx/algorithms/centrality/tests/test_second_order_centrality.py
imports: import pytest
  import networkx
label_desc: Use image node_id 6 for calling a global function with example usage: test_P3() without return types